Migration of the plastid genome to the nucleus in a peridinin dinoflagellate
Migration of the plastid genome to the nucleus in a peridinin dinoflagellate
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DOI：
10.1016/j.cub.2004.01.032
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发表时间：
2004-02-03
期刊：
影响因子：
9.2
通讯作者：
Bhattacharya, D
中科院分区：
文献类型：
--
作者：
Hackett, JD;Yoon, HS;Bhattacharya, D
甲藻是重要的初级生产者，因其形成“赤潮”的能力而具有重大的生态和经济影响[1]。它们也是进化研究的模型，因为它们具有通过内共生捕获光合细胞器（质体）的无与伦比的能力[2]。然而，占主导地位的含perdinin甲藻中质体基因组的性质和范围仍然是质体进化中最有趣的两个问题。这些类群中的质体基因组被简化为单基因小环[3,4]，编码一组不完整的（到目前为止有15个）质体蛋白。其余光合基因的位置未知。我们从有毒的甲藻亚历山大藻中生成了包含 6,480 个独特表达序列标签 (EST) 的数据集（详细信息，请参阅补充数据中的实验程序），以查找缺失的质体基因并了解内共生对基因组进化的影响。在这里，我们在 A. tamarense 的核基因组中鉴定了 48 个非小环编码的光合基因，占光系统的大部分。在其他藻类和植物的质体基因组中常见的 15 个基因已被转移到 A. tamarense 的细胞核中。质体靶向基因具有红藻和绿藻起源。这些结果凸显了甲藻作为光合真核生物中质体基因转移到细胞核的冠军的独特地位。
Dinoflagellate algae are important primary producers and of significant ecological and economic impact because of their ability to form "red tides" [1]. They are also models for evolutionary research because of an unparalleled ability to capture photosynthetic organelles (plastids) through endosymbiosis [2]. The nature and extent of the plastid genome in the dominant perdinin-containing dinoflagellates remain, however, two of the most intriguing issues in plastid evolution. The plastid genome in these taxa is reduced to single-gene minicircles [3,4] encoding an incomplete (until now 15) set of plastid proteins. The location of the remaining photosynthetic genes is unknown. We generated a data set of 6,480 unique expressed sequence tags (ESTs) from the toxic dinoflagellate Alexandrium tamarense (for details, see the Experimental Procedures in the Supplemental Data) to find the missing plastid genes and to understand the impact of endosymbiosis on genome evolution. Here we identify 48 of the non-minicircle-encoded photosynthetic genes in the nuclear genome of A. tamarense, accounting for the majority of the photosystem. Fifteen genes that are always found on the plastid genome of other algae and plants have been transferred to the nucleus in A. tamarense. The plastid-targeted genes have red and green algal origins. These results highlight the unique position of dinoflagellates as the champions of plastid gene transfer to the nucleus among photosynthetic eukaryotes.